Stacking machine with mechanism for displacing stacked workpieces at spaced intervals

ABSTRACT

The machine feeds workpieces in alignment in a stack. The workpieces typically include a variety of flat, but somewhat thick assembly of multiple layers of sheet material such as folded pads such as diapers, folded table covers, folded bed sheets, etc. For convenience of description these workpieces will be hereinafter denominated as pads. For purposes of marking the boundaries of a predetermined number or group of pads in the stack, the stack is periodically displaced laterally of the path of pads fed to the stack. Accordingly, a pad undergoing feeding to the stack is misaligned with respect to the pads in the group previously fed to the stack. A counter responds to the feeder and actuates the stack displacing mechanism at periodic intervals when the desired number of pads in the group has been fed to the stack. The counter triggers a motor which is connected to a chute on which the pads are stacked to swing the chute about a pivot, thus to periodically displace the chute with respect to the path on which the pads are advanced by the feeder.

United States Patent Kiela et al.

[451 Sept. 19, 1972 1 STACKING MACHINE WITH MECHANISM FOR DISPLACING STACKED WORKPIECES AT SPACED INTERVALS [72] Inventors: Gene F. Kiela, Kohler; Edmund Radzins, Sheboygan Falls, both of Wis.

[73] Assignee: Curt G. Joa, lnc., Sheboygan Falls,

Wis.

[22] Filed: Aug. 27, 1970 [21] Appl. No.: 67,488

Primary Examiner-Hemard Stickney Attorney-Wheeler, Wheeler, House & Clemency [5 7] ABSTRACT The machine feeds workpieces in alignment in a stack. The workpieces typically include a variety of flat, but somewhat thick assembly of multiple layers of sheet material such as folded pads such as diapers, folded table covers, folded bed sheets, etc. For convenience of description these workpieces will be hereinafter denominated as pads. For purposes of marking the boundaries of a predetermined number or group of pads in the stack, the stack is periodically displaced laterally of the path of pads fed to the stack. Accordingly, a pad undergoing feeding to the stack is misaligned with respect to the pads in the group previously fed to the stack. A counter responds to the feeder and actuates the stack displacing mechanism at periodic intervals when the desired number of pads in the group has been fed to the stack. The counter triggers a motor which is connected to a chute on which the pads are stacked to swing the chute about a pivot, thus to periodically displace the chute with respect to the path on which the pads are advanced by the feeder.

10 Claims, 2 Drawing Figures STACKING MACHINE WITH MECHANISM FOR DISPLACING STACKED WORKPIECES AT SPACED INTERVALS BACKGROUND OF THE INVENTION Pads are conventionally stacked on a chute or tray with the pads in alignment. The pads are ultimately removed manually from the chute for packaging a predetermined number of pads. Heretofore, it has been necessary for the attendant to manually count this predetermined number. This manual count results in inaccuracies and delays and requires continuous attention on the part of the attendant.

SUMMARY OF THE INVENTION In accordance with the present invention, the number of pads in a group is automatically counted and marked by the displacement of pads at the boundaries of the pad group. The pads may still be removed manually from the chute, but it is unnecessary for the attendant to count the pads, as this function has been automatically preformed by the mechanism of the present invention.

The chute on which the pads are stacked in alignment has a fixed pivot. A motor is connected to the chute to swing it through a small arc about said pivot. The motor is triggered by a counter which counts a predetermined number of pads which are fed onto the chute. When the desired number has been fed, the motor is actuated to displace the chute laterally so that the next pad fed on its original course will be misaligned or laterally displaced with respect to the aligned pads on the chute. After this single misaligned pad has been fed, the chute is restored to its original position, so that the next group of pads will be aligned with the previously aligned pads.

The result is that successive groups of aligned pads will be marked by laterally projecting misaligned pads at each end of the groups, each group having a predetermined number of pads therein.

Other objects, features, and advantages of the invention will appear from the following disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a machine embodying the invention.

FIG. 2 is a fragmentary diagrammatic perspective view on a reduced scale of the drum and pad feeder portion of said machine.

DESCRIPTION OF PREFERRED EMBODIMENT Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.

The invention will be illustrated in this application as applied to a machine to fold and stack diapers. However, the machine is adapted to handle other sheet material objects, as hereinbefore indicated.

The folder and feeder mechanism is generally conventional and includes a cylindrical drum having a plurality of axially spaced circumferential grooves 11. The pads 12 are fed to the drum over an apron 13 in the direction of arrow 14 and come opposite a pincher portion 15 of the drum. A tucking blade 16 is actuated in time with drum rotation to tuck a central portion of the pad 12 onto the pincher 15. As the drum continues to rotate, it will wipe projecting portions of the pad about a folding bar 17, thus to fold the pad in half as is indicated at 18 in the drawing.

Drum 10 is mounted on a frame 21 which pivotally supports on pintle 22 a pair of feeder arms 23 having their free ends 24 normally recessed below the surface of the drum within two of the drum grooves 11. The arms 23 have laterally projecting cam follower rollers 19 which follow the grooved track 25 of cam wheel 26. Cam wheel 26 is driven by a gear 27 which meshes with drive gear 28 which also meshes with driven gear 29 for the drum 10.

The folded pads 18 are stacked on a skeletonized pivoting tray or chute 32 which is provided at one end with a fixed pivot about pintle 33. Chute 32 is generally aligned with a fixed discharge conveyor or chute 34. While generally horizontal, the chutes 32, 34 are disposed at a slight upward incline from the drum .toward the discharge end of chute 34. At substantially its midpoint, the chute 32 is supported on the retractable plunger 35 of a fluid motor 36. Actuation of the motor 36, as hereinafter described, will swing the chute 32 on a short arc between its full and dotted line positions shown in FIG. 1.

The machine frame 21 is also provided with a chute positioning stop 37 which defines the uppermost position of the free end of the chute 32. The chute will normally be held under upward pressure of motor 36 in contact with stop 37, as the feeder arms 23 successively push folded pads 18 from the surface of the drum 10 into the chute 32, thus to stack the pads 18 in successive alignment on the chute.

Cam 26 is also connected by a belt drive 38 to a counter-controlled electric switch 41 which can be set to count any predetermined number of pads fed by the feeder arms 23 onto the chute, and then close an electric circuit to solenoid-operated valve 42 which controls the fluid motor 36. For example, if it is desired that 20 pads be disposed in each pad group, the counter 41 will count once for each ejection action of the swing arms 23 until twenty pads have been pushed from the drum 10 onto the chute 32. Thereupon, the counter switch 41 will close an electric circuit to the solenoidactuated valve 42 which is in the fluid circuit to the motor 36. Actuation of the valve 42 will cause the fluid motor 36 to draw down on the plunger 35, thus laterally displacing the chute 32 to its dotted line position shown in FIG. 1. The next pad ejected by the feeder arms 23 will then be fed into the chute at a higher level than the pads previously fed into the chute so that such pad will project above the level of the stack, as shown at 43 in FIG. 1. As soon as the chute has dropped to its broken line position and the pad 43 has been fed into the chute, the chute will actuate limit switch 44 which is also connected in the circuit to the solenoid valve 42, thus to lift the plunger 35 and restore the chute 32 to its full line position, pending stacking of the next 20 pads on the chute.

The internal porting of the motor 36 is such that the downward retracting motion of plunger 35 is rapid and the upward advancing motion of plunger 35 is slow.

As is conventional in folder-feeders of the drum type herein disclosed, the pads 18 are pushed onto the chute 32 against the resistance of a heavy roller 45 which is gravity biased to roll down the chute toward the drum 10. As the padsare pushed from the drum onto the chute, the pressure of one pad on the next is transmitted to the rollers to gradually roll the roller 45 up the incline of the chutes 32, 34. Chute 32 is desirably provided with stops 46 to limit the movement of the roller 45 toward the drum, when there are no pads in the chute 32.

The stops 46 have inclined or beveled side faces to permit the pads fed by arms 23 to be fed forward. The front faces of the stops 46 are at a right angle to the sides of chute 32 to prevent rearward movement of the pad while arms 23 return to recessed position within grooves 11 in drum 10. Thus the stops 46 function as a pad escapement.

We claim:

1. in a machine for stacking workpieces on an elongated chute along which the workpieces are aligned,

means for adding workpieces to the stack on a path in,

alignment with other workpieces along the chute, and means for periodically displacing said chute laterally of said path as a workpiece is added to the stack, thus to misalign said stack with the path and offset said workpiece with respect to other workpieces in the stack and mark the boundaries of groups of workpieces.

2. The machine of claim 1 in which the means for periodically displacing the chute comprises a counter responsive to the means for adding workpieces to the stack.

3. In a machine for stacking workpieces on an elongated chute with the workpieces generally aligned in the stack and having means for adding workpieces to the stack in alignment with other workpieces along the chute, the improvement for facilitating counting workpieces in the stack and comprising means for periodically displacing said chute laterally as a workpiece is added to the stack, thus to misalign said workpiece with respect to other workpieces in the stack to mark the boundaries of groups of workpieces, and means for adding workpieces to the stack comprising a feeder which feeds workpieces successively endwise onto said elongated chute, said chute having a pivot remote from the feeder, the means for periodically displacing the chute laterally comprising a motor which swings the chute about said pivot.

4. The invention of claim 3 in which the machine has a circumferentially grooved drum, said feeder comprising swing arms retractable in said grooves below the surface of said drum to be disposed behind a workpiece on said surface, and means to swing said arms beyond the drum surface to push said workpiece against the stack.

5. The invention of claim 4 in combination with a stop against which said motor urges the chute to restore it to its position in which the workpieces are aligned with the stack on the chute.

6. The invention of claim 3 in combination with a roller on the chute, said chute being inclined downwardly toward the feeder whereby the roller is biased by gravity against the workpieces.

7. A machine for stacking pads on a generally 3:5 ;:aei'ze ioaasargisia r52a 543: endwise onto said chute, thus to align the pads along the chute, a motor connected to the chute for laterally displacing the chute with respect to the pad feeder, a counter for counting the number of pads fed from the drum onto the chute, and control means responsive to said counter to acuate said motor to displace the chute and the pads aligned on the chute with a pad being fed by the feeder so that said pad projects laterally of the aligned pads.

8. The invention of claim 7 in which said motor has a fluid circuit, said control means comprising a valve controlling said fluid, said valve having a solenoid responsive to the counter.

9. The invention of claim 7 in which the pad folder comprises a drum having circumferential grooves, said feeder comprising a swing arm retractable within said grooves, said arm being swingable radially of the drum whereby to push a pad on the surface of the drum away from said drum and onto said chute.

10. The-invention of claim 9 in which said counter is responsive to the swinging movement of said feeder arm. 

1. In a machine for stacking workpieces on an elongated chute along which the workpieces are aligned, means for adding workpieces to the stack on a path in alignment with other workpieces along the chute, and means for periodically displacing said chute laterally of said path as a workpiece is added to the stack, thus to misalign said stack with the path and offset said workpiece with respect to other workpieces in the stack and mark the boundaries of groups of workpieces.
 2. The machine of claim 1 in which the means for periodically displacing the chute comprises a counter responsive to the means for adding workpieces to the stack.
 3. In a machine for stacking workpieces on an elongated chute with the workpieces generally aligned in the stack and having means for adding workpieces to the stack in alignment with other workpieces along the chute, the improvement for facilitating counting workpieces in the stack and comprising means for periodically displacing said chute laterally as a workpiece is added to the stack, thus to misalign said workpiece with respect to other workpieces in the stack to mark the boundaries of groups of workpieces, and means for adding workpieces to the stack comprising a feeder which feeds workpieces successively endwise onto said elongated chute, said chute having a pivot remote from the feeder, the means for periodically displacing the chute laterally comprising a motor which swings the chute about said pivot.
 4. The invention of claim 3 in which the machine has a circumferentially grooved drum, said feeder comprising swing arms retractable in said grooves below the surface of said drum to be disposed behind a workpiece on said surface, and means to swing said arms beyond the drum surface to push said workpiece against the stack.
 5. The invention of claim 4 in combination with a stop against which said motor urges the chute to restore it to its position in which the workpieces are aligned with the stack on the chute.
 6. The invention of claim 3 in combination with a roller on the chute, said chute being inclined downwardly toward the feeder whereby the roller is biased by gravity against the workpieces.
 7. A machine for stacking pads on a generally horizontal chute and comprising a folding drum for the pads, a feeder for feeding folded pads from the drum endwise onto said chute, thus to align the pads along the chute, a motor connected to the chute for laterally displacing the chute with respect to the pad feeder, a counter for counting the number of pads fed from the drum onto the chute, and control means responsive to said counter to acuate said motor to displace the chute and the pads aligned on the chute with a pad being fed by the feeder so that said pad projects laterally of the aligned pads.
 8. The invention of claim 7 in which said motor has a fluid circuit, said control means comprising a valve controlling said fluid, said valve having a solenoid responsive to the counter.
 9. The invention of claim 7 in which the pad folder comprises a drum having circumferential grooves, said feeder comprising a swing arm retractable within said grooves, said arm being swingable radially of the drum whereby to push a pad on the surface of the drum away from said drum and onto said chute.
 10. The invention of claim 9 in which said counter is responsive to the swinging movement of said feeder arm. 